#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

static bool prime(uint64_t num) {
    if (num < 2) return false;
    if (num == 2) return true;
    if (num % 2 == 0) return false;

    for (uint64_t i = 3; i * i <= num; i += 2) {
        if (num % i == 0) return false;
    }
    return true;
}

int main() {
    uint64_t sum = 0;
    for (auto i = 2; i < 2000000; ++i) {
        if (prime(i)) {
            sum += i;
        }
    }
    cout << "The sum of all primes below 2,000,000 is: " << sum << endl;
}